Descripción del proyecto
De las funciones de la cromatina a microescala a sus propiedades emergentes a macroescala
La ingente cantidad de ADN en una célula se enrolla alrededor de proteínas como cuentas en un hilo para forma un complejo denominado «cromatina». Numerosas pruebas indican que las propiedades materiales emergentes de la cromatina regulan procesos nucleares esenciales. Caracterizar estas propiedades no ha estado exento de dificultades, ya que los estudios «in vitro» carecen de la complejidad de la maquinaria celular, mientras que los estudios de células intactas no permiten observar con facilidad la dinámica a microescala. El proyecto SynthNuc, financiado con fondos europeos, acortará la brecha de escala con extractos de óvulos de «Xenopus laevis» y núcleos artificiales hechos con secuencias de ADN prediseñadas. El empleo de técnicas experimentales de alta tecnología proporcionará información novedosa sobre cómo las funciones colectivas de la cromatina a microescala dan lugar a las propiedades materiales de la cromatina a macroescala.
Objetivo
The main aim of this proposal is to resolve how the physics of molecular-scale activities result in the emergent material properties of chromatin and how those contribute to chromatin organization and function. Mounting evidence suggests that the material properties of chromatin regulate essential nuclear processes. Chromatin has been studied with two disconnected approaches; pure in vitro studies, perfectly suited for careful biophysical measurements on single DNA molecules but lacking the complexity of a cell, or intact cell measurements, with limited access to measure material properties and small-scale chromatin dynamics. The physical properties of chromatin, however, are emergent and result from the molecular activities that are in turn regulated by those properties. As a consequence, it is crucial to establish new experimental assays that connect these two scales and levels of complexity. Here, I will bridge the gap in scales and biochemistry between pure in vitro assays and measurements in intact cells by reconstituting chromatin processes in Xenopus laevis egg extracts across scales. I will combine quantitative microscopy, optical tweezer measurements, and theory to biophysically characterize the self-organization of protein-DNA co-condensation and loop extrusion and single chromatin molecules of increasing complexity. To bridge the microscopic and the macroscopic scales, I will assemble synthetic nuclei made of pre-engineered DNA sequences, which allows for exquisite control of DNA length, amount, and chromatin activities. In combination with microrheology, micropipette aspiration, and magnetic tweezers, I will unravel how the collective behavior of chromatin activities gives rise to the emergence of large-scale material properties of chromatin. This project will provide a physical description of the material state of chromatin across scales and contribute to reveal the basic physical principles that govern nuclear organization and function.
Ámbito científico
Palabras clave
Programa(s)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Régimen de financiación
HORIZON-ERC - HORIZON ERC GrantsInstitución de acogida
01069 Dresden
Alemania